Wireless Power Systems With Charging Status Information

ABSTRACT

A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device may be a wireless charging mat or other device with a charging surface. The wireless power receiving device may be a portable electronic device receiving transmitted wireless power signals from the wireless power transmitting device while resting on the charging surface. A sensor in the wireless power transmitting device or elsewhere in the system may detect user input. In response to the user input, the wireless power receiving device may display information on the state of charge of a battery in the wireless power receiving device and other charging status information on a display of the wireless power receiving device. The user input may be a finger tap on the charging surface or other user input.

This application is a continuation-in-part of patent application Ser.No. 16/562,278, filed Sep. 5, 2019, which claims the benefit ofprovisional patent application No. 62/884,391, filed Aug. 8, 2019, whichare hereby incorporated by reference herein in their entireties.

FIELD

This relates generally to power systems, and, more particularly, towireless power systems for charging electronic devices.

BACKGROUND

In a wireless charging system, a wireless power transmitting device suchas a charging mat wirelessly transmits power to a wireless powerreceiving device such as a portable electronic device. The portableelectronic device has a coil and rectifier circuitry. The coil of theportable electronic device receives alternating-current wireless powersignals from the wireless charging mat. The rectifier circuitry convertsthe received signals into direct-current power. A wireless charging matmay have the ability to simultaneously charge multiple wireless powerreceiving devices at the same time.

SUMMARY

A wireless power system has a wireless power transmitting device and awireless power receiving device. The wireless power transmitting devicemay be a wireless charging mat or other device with a charging surface.The wireless power receiving device may be a portable electronic devicereceiving transmitted wireless power signals from the wireless powertransmitting device while resting on the charging surface.

The wireless power receiving device may have a display. A sensor in thewireless power transmitting device or elsewhere in the system (includingwireless power receiving devices) may detect user input. In response tothe user input, the wireless power receiving device may displayinformation on the state of charge of a battery in the wireless powerreceiving device and other charging status information on the display ofthe wireless power receiving device.

The user input may be a finger tap on the charging surface that isgathered using a sensor such as an accelerometer in the wireless powertransmitting device or any wireless power receiving device that ischarging on the wireless power transmitting device. User input gatheredusing other sensors or other actions such as removal of the wirelesspower receiving device from the charging surface may also serve astriggering events for causing the display of the charging statusinformation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an illustrative wireless power systemin accordance with an embodiment.

FIG. 2 is a cross-sectional side view of an illustrative wireless powersystem in accordance with an embodiment.

FIG. 3 is a diagram of an illustrative display for an electronic devicein a wireless power system in accordance with an embodiment.

FIG. 4 is a flow chart of illustrative operations involved in operatinga wireless power system in accordance with an embodiment.

DETAILED DESCRIPTION

A wireless power system includes a wireless power transmitting devicesuch as a wireless charging mat. The wireless power transmitting devicewirelessly transmits power to one or more wireless power receivingdevices. The wireless power receiving devices may include devices suchas a wrist watches, cellular telephones, tablet computers, laptopcomputers, or other electronic equipment. Each wireless power receivingdevice uses power from the wireless power transmitting device forpowering the device and for charging an internal battery.

Wireless power is transmitted from the wireless power transmittingdevice to a wireless power receiving device using one or more wirelesspower transmitting coils. The wireless power receiving device has one ormore wireless power receiving coils coupled to rectifier circuitry thatconverts received wireless power signals into direct-current power.

An illustrative wireless power system (wireless charging system) isshown in FIG. 1. As shown in FIG. 1, wireless power system 8 includes awireless power transmitting device such as wireless power transmittingdevice 12 and includes a wireless power receiving device such aswireless power receiving device 24. Wireless power transmitting device12 includes control circuitry 16. Wireless power receiving device 24includes control circuitry 30. Control circuitry in system 8 such ascontrol circuitry 16 and control circuitry 30 is used in controlling theoperation of system 8. This control circuitry may include processingcircuitry associated with microprocessors, power management units,baseband processors, digital signal processors, microcontrollers, and/orapplication-specific integrated circuits with processing circuits. Theprocessing circuitry implements desired control and communicationsfeatures in devices 12 and 24. For example, the processing circuitry maybe used in selecting coils, determining power transmission levels,processing sensor data and other data to detect foreign objects andperform other tasks, processing user input, handling negotiationsbetween devices 12 and 24, sending and receiving in-band and out-of-banddata, making measurements, and otherwise controlling the operation ofsystem 8.

Control circuitry in system 8 may be configured to perform operations insystem 8 using hardware (e.g., dedicated hardware or circuitry),firmware and/or software. Software code for performing operations insystem 8 is stored on non-transitory computer readable storage media(e.g., tangible computer readable storage media) in control circuitry 8.The software code may sometimes be referred to as software, data,program instructions, instructions, or code. The non-transitory computerreadable storage media may include non-volatile memory such asnon-volatile random-access memory (NVRAM), one or more hard drives(e.g., magnetic drives or solid state drives), one or more removableflash drives or other removable media, or the like. Software stored onthe non-transitory computer readable storage media may be executed onthe processing circuitry of control circuitry 16 and/or 30. Theprocessing circuitry may include application-specific integratedcircuits with processing circuitry, one or more microprocessors, acentral processing unit (CPU) or other processing circuitry.

Power transmitting device 12 may be a stand-alone power adapter (e.g., awireless charging mat or charging puck that includes power adaptercircuitry), may be a wireless charging mat or puck that is coupled to apower adapter or other equipment by a cable, may be a portable device,may be equipment that has been incorporated into furniture, a vehicle,or other system, may be a removable battery case, or may be otherwireless power transfer equipment. Illustrative configurations in whichwireless power transmitting device 12 is a wireless charging mat aresometimes described herein as an example.

Power receiving device 24 may be a portable electronic device such as awrist watch, a cellular telephone, a laptop computer, a tablet computer,an accessory such as an earbud, a removable battery case for a cellulartelephone, a removable battery case for a pair of earbuds, or otherexternal battery pack, or other electronic equipment. Power transmittingdevice 12 may be coupled to a wall outlet (e.g., an alternating currentpower source), may have a battery for supplying power, and/or may haveanother source of power. Power transmitting device 12 may have analternating-current (AC) to direct-current (DC) power converter such asAC-DC power converter 14 for converting AC power from a wall outlet orother power source into DC power. DC power may be used to power controlcircuitry 16. During operation, a controller in control circuitry 16uses power transmitting circuitry 52 to transmit wireless power to powerreceiving circuitry 54 of device 24. Power transmitting circuitry 52 mayhave switching circuitry (e.g., inverter circuitry 61 formed fromtransistors) that is turned on and off based on control signals providedby control circuitry 16 to create AC current signals through one or morewireless power transmitting coils such as wireless power transmittingcoils 36. These coil drive signals cause coil(s) 36 to transmit wirelesspower. Coils 36 may be arranged in a planar coil array (e.g., inconfigurations in which device 12 is a wireless charging mat) or may bearranged to form a cluster of coils (e.g., in configurations in whichdevice 12 is a wireless charging puck). In some arrangements, device 12(e.g., a charging mat, puck, etc.) may have only a single coil. In otherarrangements, a wireless charging device may have multiple coils (e.g.,two or more coils, 5-10 coils, at least 10 coils, 10-30 coils, fewerthan 35 coils, fewer than 25 coils, or other suitable number of coils).

As the AC currents pass through one or more coils 36,alternating-current electromagnetic (e.g., magnetic) fields (wirelesspower signals 44) are produced that are received by one or morecorresponding receiver coils such as coil(s) 48 in power receivingdevice 24. Device 24 may have a single coil 48, at least two coils 48,at least three coils 48, at least four coils 48, or other suitablenumber of coils 48. When the alternating-current electromagnetic fieldsare received by coil(s) 48, corresponding alternating-current currentsare induced in coil(s) 48. Rectifier circuitry such as rectifiercircuitry 50, which contains rectifying components such as synchronousrectification metal-oxide-semiconductor transistors arranged in a bridgenetwork, converts received AC signals (received alternating-currentsignals associated with electromagnetic signals 44) from one or morecoils 48 into DC voltage signals for powering device 24.

The DC voltage produced by rectifier circuitry 50 (sometime referred toas rectifier output voltage Vrect) can be used in charging a batterysuch as battery 58 and can be used in powering other components indevice 24. For example, device 24 may include input-output devices 56.Input-output devices 56 may include input devices for gathering userinput and/or making environmental measurements and may include outputdevices for providing a user with output. As an example, input-outputdevices 56 may include a display for creating visual output, a speakerfor presenting output as audio signals, light-emitting diode statusindicator lights and other light-emitting components for emitting lightthat provides a user with status information and/or other information(e.g., one or more charging status indicator light-emitting diodes forindicating charging status), haptic devices for generating vibrationsand other haptic output, and/or other output devices. Input-outputdevices 56 may also include sensors for gathering input from a userand/or for making measurements of the surroundings of system 8.Illustrative sensors that may be included in input-output devices 56include three-dimensional sensors (e.g., three-dimensional image sensorssuch as structured light sensors that emit beams of light and that usetwo-dimensional digital image sensors to gather image data forthree-dimensional images from light spots that are produced when atarget is illuminated by the beams of light, binocular three-dimensionalimage sensors that gather three-dimensional images using two or morecameras in a binocular imaging arrangement, three-dimensional lidar(light detection and ranging) sensors, three-dimensional radio-frequencysensors, or other sensors that gather three-dimensional image data),cameras (e.g., infrared and/or visible cameras with respective infraredand/or visible digital image sensors and/or ultraviolet light cameras),gaze tracking sensors (e.g., a gaze tracking system based on an imagesensor and, if desired, a light source that emits one or more beams oflight that are tracked using the image sensor after reflecting from auser's eyes), touch sensors, buttons, capacitive proximity sensors,light-based (optical) proximity sensors such as infrared proximitysensors, other proximity sensors, force sensors, sensors such as contactsensors based on switches, gas sensors, pressure sensors, moisturesensors, magnetic sensors, audio sensors (microphones), ambient lightsensors, optical sensors for making spectral measurements and othermeasurements on target objects (e.g., by emitting light and measuringreflected light), microphones for gathering voice commands and otheraudio input, distance sensors, motion, position, and/or orientationsensors that are configured to gather information on motion, position,and/or orientation (e.g., accelerometers, gyroscopes, compasses, and/orinertial measurement units that include all of these sensors or a subsetof one or two of these sensors), sensors such as buttons that detectbutton press input, joysticks with sensors that detect joystickmovement, keyboards, and/or other sensors. Device 12 may have one ormore input-output devices 70 (e.g., input devices and/or output devicesof the type described in connection with input-output devices 56).

Device 12 and/or device 24 may communicate wirelessly using in-band orout-of-band communications. Device 12 may, for example, have wirelesstransceiver circuitry 40 that wirelessly transmits out-of-band signalsto device 24 using an antenna. Wireless transceiver circuitry 40 may beused to wirelessly receive out-of-band signals from device 24 using theantenna. Device 24 may have wireless transceiver circuitry 46 thattransmits out-of-band signals to device 12. Receiver circuitry inwireless transceiver 46 may use an antenna to receive out-of-bandsignals from device 12. The out-of-band wireless signals that areconveyed between devices 12 and 24 (and, if desired, the wirelesssignals conveyed between device 12 and/or device 24 and/or otherequipment) may be personal area network communications (e.g., Bluetooth®communications), wireless local area network communications (e.g., IEEE802.11 WiFi® communications), near-field communications (NFC) signals at13.56 MHz or other suitable near-field communications frequency, othershort-range wireless communications, and/or wireless signals associatedwith other types of wireless communications. In-band transmissionsbetween devices 12 and 24 may be performed using coils 36 and 48. Withone illustrative configuration, frequency-shift keying (FSK) is used toconvey in-band data from device 12 to device 24 and amplitude-shiftkeying (ASK) is used to convey in-band data from device 24 to device 12.Power may be conveyed wirelessly from device 12 to device 24 duringthese FSK and ASK transmissions. In-band and out-of-band wirelesscommunications may be used to convey power transmission controlcommands, status information, information indicating to device 12 thatdevice 24 is present on the charging surface of device 12, informationindicating to device 24 that device 24 is present on the chargingsurface of device 10, information indicating to device 12 and/or device24 that device 12 is transmitting power to device 24 that is beingreceived by device 24, and other information.

It is desirable for power transmitting device 12 and power receivingdevice 24 to be able to communicate information such as received power,battery states of charge, and so forth, to control wireless powertransfer. However, the above-described technology need not involve thetransmission of personally identifiable information in order tofunction. Out of an abundance of caution, it is noted that to the extentthat any implementation of this charging technology involves the use ofpersonally identifiable information, implementers should follow privacypolicies and practices that are generally recognized as meeting orexceeding industry or governmental requirements for maintaining theprivacy of users. In particular, personally identifiable informationdata should be managed and handled so as to minimize risks ofunintentional or unauthorized access or use, and the nature ofauthorized use should be clearly indicated to users.

Control circuitry 16 has external object measurement circuitry 41 thatmay be used to detect external objects on the charging surface of thehousing of device 12 (e.g., on the top of a charging mat or, if desired,to detect objects adjacent to the coupling surface of a charging puck).The housing of device 12 may have polymer walls, walls of otherdielectric, metal structures, fabric, and/or other housing wallstructures that enclose coils 36 and other circuitry of device 12. Thecharging surface may be a planer outer surface of the upper housing wallof device 12. Circuitry 41 can detect foreign objects such as coils,paper clips, and other metallic objects and can detect the presence ofwireless power receiving devices 24 (e.g., circuitry 41 can detect thepresence of one or more coils 48). During object detection andcharacterization operations, external object measurement circuitry 41can be used to make measurements on coils 36 and/or on optional foreignobject detection coils in device 12 to determine whether any devices 24are present on device 12.

In an illustrative arrangement, measurement circuitry 41 of controlcircuitry 16 contains signal generator circuitry (e.g., oscillatorcircuitry for generating AC probe signals at one or more probefrequencies, a pulse generator that can create impulses so that impulseresponses can be measured to gather inductance information, Q-factorinformation, etc.) and signal detection circuitry (e.g., filters,analog-to-digital converters, impulse response measurement circuits,etc.). In some configurations, Q-factor measurements and othermeasurements may be made during wireless power transfer operations.Switching circuitry in device 12 may be used to switch desired coilsinto use during wireless power transmission and/or foreign objectdetection operations.

Measurement circuitry 43 in control circuitry 30 and/or measurementcircuitry 41 in control circuitry 16 may be used in making current andvoltage measurements. Based on this information or other information,control circuitry 30 can configure rectifier circuitry 50 to helpenhance wireless power reception by coils 48.

FIG. 2 is a cross-sectional side view of system 8. In the illustrativeconfiguration of FIG. 2, device 12 has one or more wireless powertransmitting coils 36 that are used in transmitting wireless power. Asshown in FIG. 2, device 12 and device 24 each have a respective housingformed from polymer walls, walls of other dielectric, metal structures,fabric, and/or other housing wall structures that enclose internalcircuitry. The upper surface of device 24 forms wireless chargingsurface 74. During operation, one or more wireless power receivingdevices such as device 24 may be placed on wireless charging surface 74(e.g., the uppermost surface of the housing of device 12) to receivewireless power. Each device 24 may have one or more wireless powerreceiving coils 48. Front face F of device 24 or other portions ofdevice 24 may have a display such as display 76. Display 76 and/or otherinput-output devices 56 may be used in providing information on chargingstatus (e.g., battery level information, information on whether chargingis active or inactive, rate of charging, time left to full charge, etc.)and other information to a user.

During long periods of user inactivity (e.g., when devices 24 areresting on charging surface 74 in the absence of active userinteractions), the display(s) in system 8 may be turned off (e.g., ablack screen may be displayed). This may help reduce visual clutter, mayenhance display lifetime, and may help conserve power.

After charging is underway and display 76 is blank, a user may desire tomonitor the status of system 8. For example, a user may want to knowwhether the batteries in one or more devices 24 are fully charged,whether wireless power is being transferred (e.g., whether chargingoperations are currently taking place), and/or other information on theoperation of system 8. To awaken the display(s) of system 8 and directsystem 8 to display charging status information, triggering input may beprovided to system 8.

As an example, a user may tap on surface 74 or any power receivingdevice (e.g., device 24) with the user's finger 72 or other externalobject. In response to detecting touch (tap) input, system 8 may displaycharging status information and other information on one or moredisplays such as display 94. For example, each device 24 in system 8 maybe directed to determine the state of its battery 58 and to displayinformation on that battery's state of charge and to display informationon whether charging operations are active. If desired, charging statusinformation for multiple devices 24 may be displayed on a singledisplay. For example, charging status information for a wrist watch anda pair of earbuds may be displayed along with cellular telephonecharging status information on the display of the cellular telephone. Insome configurations, device 12 may include a display for displayingcharging status information.

In addition to or instead of tapping on surface 74 to direct system 8 todisplay charging status information on one or more displays, sensors insystem 8 (e.g., one or more sensors in device 12 and/or in one or moreof devices 24) may be used to detect other input. Examples of input thatmay be sensed include double taps, force input (e.g., light and/or heavytaps, light and/or heavy sustained finger press events, etc.), touchgestures (e.g., swipes, multitouch gestures, etc.), air gesture input(e.g., three-dimensional hand motions within range of athree-dimensional gesture detection sensor, camera, or other sensor fordetecting hand motions), eye (gaze) input, voice commands, detection ofremoval of device 24 from charging surface 74 (e.g., by detecting theinterruption of wireless power transmission that is indicative ofremoval of device 24 from surface 74, by detecting lifting motion with amotion sensor in device 24, by detecting lifting motion with a camera orother sensor, etc.), and input associated with detection of removal of acharging cable and/or other cable from a connector port in device 24(e.g., using a connector sensor that detects presence or absence of thecable connector, by detecting removal of wired power delivery to device24, etc.).

In some scenarios, triggering input is received by a sensor in device12. For example, if a user taps on surface 74, an accelerometer or othermotion sensor in device 12 can detect vibrations or other motion insurface 74. In response, control circuitry 16 may communicate withcontrol circuitry 30 to direct control circuitry 30 to gather anddisplay charging status information on display 76. In other scenarios,triggering input is received by a sensor in device 24. For example, if auser taps on surface 74, this will jiggle surface 74 and result indetectable movement of device 24. An accelerometer or other motionsensor in device 24 can then detect the user input and take suitableaction. In taking action (e.g., directing charging status information bedisplayed on one or more devices 24 or other action), device 24 cancommunicate with other devices 24 directly (e.g., using Bluetooth®,etc.) or via device 12. In some embodiments, input from multiple sensorsand/or sensors in one or more devices 12 and/or 24 can be combined usinga sensor fusion arrangement. For example, system 8 may display chargingstatus information in response to detection of motion of device 12 witha motion sensor in device 12 and detection of associated motion ofdevice(s) 24 with a motion sensor in device(s) 24.

In some embodiments, device 24 is a removable battery case that isconfigured to receive a pair of ear buds. A user may remove the earbudsfrom device 24 for use. When the user has finished using the earbuds,the user may store the earbuds within interior compartments in device24. In this type of embodiment, device 24 has a battery that rechargesbatteries in the earbuds. The battery of device 24 is charged wirelesslyby placing device 24 on device 12 as shown in FIG. 2.

To indicate the status of device 24 in this type of arrangement, device24 has a visual output device such as a display or a status indicatorlight (e.g., a light-emitting device in input-output devices 56, whichis sometimes referred to as a charging status indicator, light-emittingdiode status indicator, status indicator, charging status indicatorlight, etc.). A status indicator light is formed from one or morelight-emitting diodes (or, if desired, lasers or other light-emittingcomponents). The color, intensity, blink pattern, number of illuminatedlight-emitting diodes, and/or other characteristics of thelight-emitting diodes in a charging status indicator light can beadjusted by the control circuitry of device 24 to supply a user withvisual battery charging status information.

The charging status indicator light can be activated whenever wirelesscharging is performed (e.g., whenever wireless power is being receivedby device 24), whenever device 24 is present on device 12, and/or at anyother suitable time. If desired, the charging status indicator light canbe turned off (e.g., temporarily deactivated) whenever device 24 is offof device 12 and/or is not receiving power.

The charging status indicator light can also be turned off after apredetermined amount of output time. If, for example, the chargingstatus indicator light has been illuminated for 20 seconds, the chargingstatus indicator light may automatically turn off. At a later time, thecharging status indicator light may be reawakened and used to visuallydisplay charging status information. For example, the charging statusindicator light can be turned on and used to visually present chargingstatus information to the user in response to determining that device 24has been placed on the charging surface of device 12 and/or in responseto a tap on device 24 and/or 12 that is detected by an accelerometer indevice 24 and/or that is detected by an accelerometer in device 12.

Consider, as an example, a scenario in which the earbuds battery case(e.g., the housing of the case) is not located on device 12 and is notbeing charged. In this scenario, the charging status indicator light maybe turned off after a predetermined period of time (e.g., 20 s). When auser desires to view the charging status information for the earbudsbattery case, the user may tap on the earbuds battery case. Anaccelerometer in the case detects the tap and activates the chargingstatus indicator.

If desired, the earbuds battery case (e.g., the housing of the case) maybe located on the charging surface of device 12. After displaying thecharging status information for a predetermined amount of time (e.g., 20s), the charging status indicator may be turned off. To view thecharging status information, the user may tap on the battery case(device 24) and/or device 12.

In some embodiments, the charging status indicator light is only turnedon when device 24 (e.g., the housing of device 24) is on the chargingsurface of device 12 and/or is receiving power from device 12. With thisarrangement, motion of device 24 (e.g., a tap on device 24) while device24 is on device 12 causes device 24 to activate the charging statusindicator light and visually display charging status information for theuser, whereas motion of device 24 (e.g., taps or other motion of device24) while device 24 is being carried in a user's pocket or is otherwisenot on device 12 will not activate the charging status indicator lightso that the charging status information will not be displayed.

In some examples, device 24 determines that it is on device 12 whendevice 24 is receiving power wirelessly. In some examples, device 24determines that device 24 is on device 12 when device 24 is receiving awireless signal from device 12. The wireless signal may be a Bluetooth®signal, a near-field communications signal, or other out-of-band signaland/or may be a wireless signal transmitted by coil(s) 36 and receivedby coil(s) 48. The wireless signal may, if desired, be associated with apredetermined digital ping (e.g., a wireless signal impulse or otherwireless signal created by driving signals onto one or more of coils 36to measure the impedance of coil(s) 36 or to otherwise make wirelessmeasurements on device 24, etc.). The wireless signal may be receivedusing coil(s) 48 or a separate antenna in device 24 (e.g., an antenna intransceiver circuitry 46).

Any suitable control architecture may be used in system 8. For example,device 12 may serve as a master device and devices 24 may serve asslaves that respond to commands from the master device, a given one ofdevices 24 may serve as a master device and device 12 and non-masterdevices 24 may serve as slave devices, devices 12 and 24 may serve aspeer devices operating in a peer-to-peer network, etc.

FIG. 3 shows illustrative information such as charging statusinformation that can be displayed on display 76 of device 24 in responseto a triggering event such as detected tap input on surface 74. Theillustrative information that is displayed on display 76 of device 24 ofFIG. 3 includes battery state-of-charge indicator icon 78. Icon 78 canuse a bar-type indicator (or other suitable indicator such as a circularindicator, triangular indicator, etc.) to indicate visually to the userthe amount of charge on battery 58. For example, if battery 58 is halfcharged, a colored bar may be presented that fills half of the graphicalbattery of icon 78. Battery state-of-charge may also be displayed usingalphanumeric characters 80. Optional additional information (e.g., anicon, text, etc.) may also be presented, as illustrated by optionaladditional information 82 of FIG. 3. Information 82 may indicate whetherdevice 24 is currently receiving wireless power or not and may includeother status information related to wireless power transfer operations,battery state-of-charge, and/or other system parameters (e.g., rate ofcharge, approximate time left to reach full charge, etc.). The amount ofarea consumed by icon 78, characters 80, and/or information 82 may besufficient to allow a user to view this information from a distance(e.g., this amount of area may be at least 10%, at least 20%, or lessthan 99% of the total area of display 76).

Illustrative operations associated with using system 8 are shown in FIG.4.

During the operations of block 90, system 8 may monitor for user inputor other triggering input to trigger the presentation of charging statusinformation or other information to a user. Sensors such as sensors ininput-output devices 70 and/or sensors in input-output devices 56,and/or other circuitry in system 8 (e.g., control circuitry 16 and/or30) may be used in monitoring for triggering events. Examples oftriggering events include detection of a user tap, a user double tap, aswipe gesture, or other user finger input (e.g. a tap or other fingerinput on device 12 or one of device(s) 24), detection of voice inputsuch as a voice command, detection of an air gesture (three-dimensionalgesture), detection of device motion (e.g., detection of lifting ofdevice 24 from charging surface 74), detection of the unplugging of acable such as a cable used for wired power transfer from device 12 todevice 24, detection of force sensor input, optical sensor input, touchsensor input, accelerometer input or other motion sensor input, and/orother sensor input. Air gestures may be detected when a user waves ahand or other external object over device 12 and/or when a user wavesdevice 24 near device 12. Device 12 can use an optical proximity sensorand/or devices 12 and/or 24 can use other sensors in input-outputdevices 70 and/or 56 to detect when device 24 is waved near device 12.

In response to detection of a triggering event, processing may proceedto the operations of block 92, where charging status information and/orother information (e.g., a home screen including charging statusinformation and/or other information) may be presented to a user. Duringthe operations of block 92, devices in system 8 may communicate witheach other to exchange charging status information and other informationand/or to exchange commands. For example, if user input was detected bydevice 12 during the operations of block 90, device 12 can inform one ormore devices 24 with display(s) that the user input has been received,thereby directing device(s) 24 to display charging status information orother information (see, e.g., the information displayed in the exampleof FIG. 3). Before device 12 causes device(s) 24 to display theinformation, device(s) 24 may be providing a blank (e.g., displayingblack, off, in touch-sensitive but display-off mode, and so forth)screen on display 76.

In response to the information provided by device 12 to device 24 orreceived from other devices 24 in the system, device 24 can gathercharging status information such as information on the state-of-chargeof battery 58 and information on whether wireless power is currentlybeing received by device 24 from device 12. This information may then bedisplayed on the display of each device 24 in system 8 (e.g., the blankscreen of each device 24 may be replaced by a screen containing iconsand other information of the type shown in FIG. 3) and/or may otherwisebe presented to the user with an output device in device(s) 24. Inembodiments in which multiple devices 24 are present, charging statusinformation may be gathered from multiple devices 24 and presented onthe display of one or more of these devices 24. In some embodiments,device 12 may have an output device such as a display and may displaycharging status information and/or other information in addition to orinstead of using one or more of devices 24 to display this information.

Consider, as an example, a scenario in which multiple devices 24 arepresent on a wireless charging mat or other device 12 with multiplewireless power transmitting coils. Device 12 may use the transmittingcoils to communicate respectively (e.g., via in-band communications)with devices 24 and/or may use out-of-band wireless communicationscircuitry to communicate with devices 24. In this way, a tap on device12 or a tap on one of devices 24 or other triggering event (e.g.,lifting one of devices 24 away from device 12) that is detected bydevice 12 and/or one of devices 24 can be used to cause the display ofinformation such as charging status information on each of devices 24 insystem 8 (and, if desired, on device 12). Charging status can also bedisplayed on each of devices 24 in system 8 (and, if desired, on device12) in response to detection of an air gesture with a hand or device 24in the vicinity of device 12 (e.g., detection of waving motion of device24 in the vicinity of device 12 using an optical sensor such as anoptical proximity sensor in device 12 and/or the waved device 24 and/orother device(s) 24 and/or detection of the waving motion of device 24using one or more other sensors in input-output devices 70 and/or 56).

The foregoing is merely illustrative and various modifications can bemade to the described embodiments. The foregoing embodiments may beimplemented individually or in any combination.

What is claimed is:
 1. A wireless power transmitting device fortransmitting wireless power to a wireless power receiving device with adisplay, comprising: wireless power transmitting circuitry configured totransmit wireless power signals to the wireless power receiving device;a sensor configured to detect user input; and control circuitryconfigured to wirelessly communicate with the wireless power receivingdevice in response to detecting the user input to cause the wirelesspower receiving device to display charging status information on thedisplay.
 2. The wireless power transmitting device of claim 1 whereinthe sensor comprises an accelerometer.
 3. The wireless powertransmitting device of claim 2 further comprising a housing with acharging surface, wherein the user input comprises a tap on the chargingsurface.
 4. The wireless power transmitting device of claim 3 whereinthe display is providing a blank screen prior to displaying the chargingstatus information and wherein the control circuitry is configured tocommunicate with the wireless power receiving device in response todetecting the user input to cause the wireless power receiving device todisplay the charging status information in place of the blank screen. 5.The wireless power transmitting device of claim 4 wherein the chargingstatus information includes battery state-of-charge information for abattery in the wireless power receiving device.
 6. The wireless powertransmitting device of claim 4 wherein the charging status informationincludes battery state-of-charge information for a battery other than abattery in the wireless power receiving device.
 7. The wireless powertransmitting device of claim 4 wherein the charging status informationincludes information on whether wireless power is being transmitted fromthe wireless power transmitting circuitry to the wireless powerreceiving device.
 8. The wireless power transmitting device of claim 1wherein the control circuitry is configured to communicate with thewireless power receiving device using in-band wireless communications inresponse to detecting the user input.
 9. The wireless power transmittingdevice of claim 1 wherein the control circuitry is configured tocommunicate with the wireless power receiving device using out-of-bandwireless communications in response to detecting the user input.
 10. Thewireless power transmitting device of claim 1 wherein the sensor isconfigured to detect movement and wherein the displayed charging statusinformation covers at least 10% of the display.
 11. A wireless powertransmitting device, comprising: a housing with a charging surface;wireless power transmitting circuitry that is configured to transmitwireless power signals to a wireless power receiving device on thecharging surface; and control circuitry configured to detect atriggering event and, in response to detection of the triggering event,wirelessly communicate with the wireless power receiving device to causethe wireless power receiving device to display charging statusinformation associated with charging of a battery in the wireless powerreceiving device using the wireless power signals.
 12. The wirelesspower transmitting device of claim 11 further comprising a sensor,wherein the control circuitry is configured to detect the triggeringevent using the sensor.
 13. The wireless power transmitting device ofclaim 11, wherein the triggering event comprises a user voice commandand wherein the sensor comprises a microphone configured to receive theuser voice command.
 14. The wireless power transmitting device of claim12 wherein the sensor comprises an accelerometer.
 15. The wireless powertransmitting device of claim 12 wherein the sensor comprises a sensorselected from the group consisting of: an optical sensor, a forcesensor, and a touch sensor.
 16. The wireless power transmitting deviceof claim 11 wherein the charging status information comprises batterystate-of-charge information.
 17. A wireless power receiving deviceconfigured to receive wireless power from a wireless power transmittingdevice while resting on a charging surface of the wireless powertransmitting device, comprising: wireless power receiving circuitryconfigured to receive the wireless power; a battery having a state ofcharge; a display; control circuitry, operatively coupled to thewireless power receiving circuitry, the battery, and the display, andconfigured to: in response to detection of a triggering event, displayinformation on the state of charge on the display, wherein thetriggering event comprises a triggering event selected from the groupconsisting of: removal of the wireless power receiving device from thecharging surface and user input.
 18. The wireless power receiving deviceof claim 17 wherein the user input comprises a finger tap on thecharging surface and wherein the wireless power receiving devicecomprises a sensor configured to detect motion resulting from the fingertap on the charging surface.
 19. The wireless power receiving device ofclaim 18 wherein the sensor comprises an accelerometer and wherein thecontrol circuitry is configured to: in response to detection of thefinger tap on the charging surface with the sensor, display informationon whether wireless power is being received by the wireless powerreceiving circuitry.
 20. The wireless power receiving device of claim 18wherein the control circuitry comprises wireless communicationscircuitry for receiving battery state-of-charge information for aportable electronic device resting on the charging surface and whereinthe control circuitry is configured to: in response to detection of thefinger tap on the charging surface with the sensor, display both thestate of charge of the battery and the battery state-of-chargeinformation for the portable electronic device on the display.